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This article discusses muon tomography as a method for detecting possible hidden chambers in the Pyramid of the Sun. It explores the genetic relation between muons and neutrinos and the implications for muon flux calculations. The article also provides an overview of the Super-Kamiokande detector and its potential for low-energy neutrino analysis.
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HE2: Muons and Neutrinos 2.1 Muon observations 17 2.2 Solar & atmospheric neutrinos 16 2.3 Astrophysical neutrinos 37 2.4 Calculations 19 2.5 New experiments, instrumentation 18 Tom Gaisser
Searching for possible hidden chambers in the Pyramid of the Sun Muon tomography ICRC-2007, Mérida
J. Kempa Muons, the gold standard of cosmic-ray physics • Muon tomography works because the spectrum of muons is very well-measured up to several hundred GeV • Genetic relation to neutrinos constrains neutrino flux: • p+ m+ + nm ; m+ e+ + ne + nm, • K+ m+ + nm ; etc. • Major uncertainties in m and n fluxes: • E > TeV: K component • E > 100 TeV: charm component • Overall normalization Tom Gaisser
m+/m- with MINOS • MINOS far detector • 10 < Em < 250 GeV at 2 < X cosq < 4 km w. e. • Equivalent to 1 < Em < 7 TeV at surface • First high-statistics measurement of muon charge ratio in TeV energy range • Realize goal of Zatsepin & Kuz’min (1960)* • “…in the energy range of 1011 – 5x1012 eV the m-meson angular distributions depend significantly on their production mechanism” (*JETP 39, 1677-1685, 1960) Tom Gaisser
x 1.37 x 1.27 Charge Ratio Model Results • MINOS measure m+ / m- and fit to formulas • best fit values: f+ = Ap+ /Ap- = 0.55; fK+ = AK+ /AK- = 0.67 Tom Gaisser
vertical 60 degrees p / K ratio • Critical energy for interaction vs decay: • ep = mpc2 / ctp ~ 115 GeV • eK = mKc2 / ctK ~ 850 GeV • Effect bigger for K by kinematics: 1 - mm/mK ~1 1 - mm/mp << 1 • Steep spectrum • K contribution increases when E > ep Tom Gaisser
Implications for > TeV atmospheric n • fK+ = 0.67 ANK+ / ANK- = 2 • Substantial contribution of associated production ( p L K+ ) • Effect is amplified for n’s: nm / nm 2 • Important for atmospheric neutrino background in neutrino telescopes • MINOS measurement will lead to improved calculation of >TeV fn Tom Gaisser
Super-Kamiokande and status of neutrino oscillations • SK-III operating since July 12, 2006 • Hardware and software upgrades • Full complement of >11 thousand 20” PMTs plus outer (veto) detector • Recalibration finished and first year data in good agreement with SK-I + SK-II • Potential for lower threshold for solar neutrino analysis Tom Gaisser
C Scientific American 1. Introduction: History of Super-Kamiokande M. Miura • 1996.4 Started data taking (SK- I) Evidence of Atm. n ocsillation(98’) • 1999.6 K2K started Evidence of Solar n oscillation(01’) • 2001.7 Stopped data taking for detector upgrade • 2001.11 Accident • partial reconstruction of the detector • 2002.10 Resumed data taking (SK- II) • 2002.12 Resumed K2K beam (K2K-II) • 2004.11 K2K finished Confirm n oscillation by accelerator n • 2005.10 Stopped data taking for full reconstruction Water Cherenkov detector • 1000 m underground • 50,000 ton (22,500 ton fid.) • 11,146 20 inch PMTs • 1,885 anti-counter PMTs • E > 5 MeV • E resolution: 14 %@10MeV • 5,182 20 inch PMTs • E > 7 MeV • E resolution: 21 %@10MeV n 42m SK- I 39m SK- II
SK-I, SK-II combined analysis Yumiko Takenaga Tom Gaisser
SK extension to low energy • Reconstruction algorithms were refined during SK-II to overcome loss of PMTs • Potential to extend threshold to ~3 MeV • Solar neutrinos in transition region • Reactor anti-neutrinos • Detection of low-energy ne + p n + e+ requires addition of Gd to detect recoil n • Bonus: this will allow improved search for relic supernova ne Tom Gaisser
Michael Smy 1.0 after simple cuts (vertex correl., fiducial volume, ...) Why Study Low Energy Events? SSM n spectrum pp 0.8 0.8 oscillated/unoscillated 7Be Vacuum osc. dominant 0.6 0.6 P(ne ne) • precision measurement of solar neutrino oscillation parameters with reactor neutrinos • need 0.1% GdCl3 to tag neutrons in delayed coincidence • MSW transition for solar neutrinos oscillations • both require very low energy threshold & precise energy calibration Expected P(ne ne) pep expected spectrum from one year of SK n data (15 reactors) with Gd (current best-fit oscillation parameters) 0.4 0.4 8B 0.2 0.2 matter osc. dominant Reconstructed Total Positron Energy (MeV) g’s with SE=8MeV Gd ne Courtesy K. Bays, UC Irvine & M. Nakahata, ICRR
Neutrino oscillation status • L/E dip seen at first oscillation minimum • No evidence yet for any non-standard oscillations, only upper limits for • sterile neutrinos • oscillations increasing with energy • No sign yet of possible second-order oscillation effects • three-neutrino effects • q13 • MINOS in NuMi beam results consistent with SK Tom Gaisser
Predicting Unoscillated FD Spectrum π+ p Target FD Decay Pipe ND × = MINOS in NuMi neutrino beam, Alexandre Sousa • Start with Near Detector data and perform extrapolation to the Far Detector • Use knowledge of pion decay kinematics and beamline geometry to construct a beam transport matrix and predict FD spectrum from measured ND spectrum • The “Beam Matrix” method is the primary method used in the MINOS CC analysis
MINOS Best Fit Spectrum PRL 97, 191801 (2006) • Best fit energy spectrum and Data/MC Ratio for 1.271020 POT
Atmospheric neutrinos in MINOS • First detector with ability to determine sign of atmospheric neutrinos • Too small to obtain good statistics • Note reversal of muon charge ratio: • muon neutrino / muon anti-neutrino > 1 • therefore m- / m+ > 1 Tom Gaisser
Expected flux of relic supernova neutrinos Plot shows sum of neutrinos + antineutrinos Possible E-2 diffuse astrophysical spectrum (WB “bound” / 2 for osc) nm ne Solar n RPQM for prompt n Bugaev et al., PRD58 (1998) 054001 Slope = 2.7 Prompt n Slope = 3.7 Atmospheric n as background Refined calculations in GeV range: M.Honda, G. Barr Tom Gaisser
Atmospheric nm : ne : nt ~ 2:1:0 Steady flux sec(q) distribution Steep spectrum ne very steep “prompt” neutrinos nm : ne = 1:1 normalization uncertain harder spectrum Astrophysical nm : ne : nt ~ 1:1:1 Flux may be variable Point sources expected Harder spectrum All flavors similar spectra Charm decay is important background for search for astrophysical neutrinos Atmospheric vs astrophysical n Tom Gaisser
T. Iida, HE2.3 Tom Gaisser
Stopped m below threshold atmosphere ne interactions Diffuse, relic supernova neutrinos • Super-K limit is from ne + p n + e+ • Neutron not detected in current Super-K • Backgrounds: • atmospheric ne and ne • solar ne and reactor ne • atmospheric nm m (Em < 50 MeV) Tom Gaisser
Improvement with tagged neutron Beacom & Vagins, PRL 93 (2004) 171101 Prescribe gadolinium additive to detect neutrons and eliminate background and select anti-ne only Current limits close to expectation! Tom Gaisser
Time Information: Sliding Window Search Dt Multiplicity≥threshold M. Ikeda, Super-K Time duration of main burst is about 10 sec. Prompt burst of ne is so called neutronization burst whose time duration is expected as ~10msec. Livermore simulation (Totani et.al. 1998) 0.1 1.0 10 sec Time Profile of SN burst Sliding Time window search 1. Set timewindow (Dt) and multiplicity threshold (Mthr.) ≥ Mthr.events/Dt Event time
S-K Summary (SN burst search) Using data from Super-K, 3 methods of supernova searches with newly installed criteria was conducted. Data set : from May 1996 to Oct 2005 Total livetime: 2589.3 days (Livetime for 3rd analysis : 2381.3 days) No candidate was observed 100% detection probability up to 100 kpc SN rate within 100kpc(LMC,SMC,our Galaxy) is estimated < 0.32 SN/yr @ 90% C.L. Detection probability is maintained at a level of 7% for SN at Andromeda. No candidate of neutronization burst observed
Total 4919 days Upper Limit to SN event in the Milky Way 0.17 /year (90% c.l.)
Detectors sensitive to high-energy neutrinos • Neutrino telescopes • Primarily aimed at >TeV, upward nm-induced n • e.g. IceCube/AMANDA, Baikal, Antares, Nestor, KM3net • Also sensitive to PeV, EeV n, but limited area • Radio, acoustic detection • Threshold in EeV range • Giant EAS detectors sensitive to ~EeV n • e.g. Auger, HiRes, CRTNT Tom Gaisser
IceCube 2006-2007: 13 strings deployed 2005-2006: 8 strings 2004-2005 : 1 string 2007/08: add 14 to 18 strings and tank stations Completion by 2011. IceTop Current configuration - 22 strings - 52 surface tanks Air shower detector 80 pairs of ice Cherenkov tanks Threshold ~ 300 TeV 1450m InIce AMANDA-II 19 strings 677 modules Planned 80 strings of 60 optical modules each 17 m between modules 125 m string separation AMANDA now operating as part of IceCube -talk of A. Gross 2450m
Atmospheric neutrinos in IceCube Paolo Desiati, John Pretz Tom Gaisser
Goals for neutrino astronomy • Point source searches • Unbinned search improves sensitivity (Braun, Aguilar) • Search for clusters in time and space (E. Bernardini, R. Porrata) • Search for neutrinos from identified GRB (I. Taboada) • Multi-messenger “Target of Opportunity” in coincidence with gamma-ray telescope • see Gavin Rowell’s rapporteur talk for details of the n/g connection • Atmospheric n and search for diffuse astrophysical n covered here Tom Gaisser
Point source search with IceCube-9 Chad Finley IC9 point source limit IC9: Neutrino effective area Tom Gaisser
Expected n flux from galactic point sources, example: RXJ 1713-3946 Christian Stegmann et al. Tom Gaisser
Note importance of background of atmospheric n in a km3 detector Tom Gaisser
Search for diffuse n with hard spectrum Gary Hill et al. Tom Gaisser
AMANDA 4 yrs atmospheric n & Limits on diffuse E-2n preliminary [1] Achterberg et al., astro-ph/0705.1315
AMANDA cascade searches (>PeV) Lisa Gerhardt Tom Gaisser
AMANDA cascade searches Similar cascade search with different energy-dependent variable in paper by Oxana Tarasova for AMANDA Tom Gaisser
NT200+=NT200 +3 long outer strings BAIKAL, Ralf Wischnewski R.Wischnewski ICRC, Merida, 2007 Km3 planned • - Height = 210m • = 200m • Geom.Volume ~ 5 Mton
Atmospheric Muon-Neutrinos E_thr ~ 15GeV R.Wischnewski ICRC, Merida, 2007 Skyplot of NT200 neutrino events / 5 years (galactic coordinates) Galactic center visible 18 hours per day - Data: 372 upward events (1998-2002).( Nm(>15GeV)/Nm(>1GeV)~1/7 ) - MC: 385 ev. expected (15%BG). A high statistics neutrino sample for Point-Source Search, incl. GalCenter. No evidence for non-atmosph. ‘s.
ANTARES: Conclusions and Outlook Antoine Kouchner • Major step forward during the last year • Detector working well within design specifications: • Junction Box in operation since Dec. 2002 • 5 lines delivering data on the site • All technical problems solved • 12 lines detector complete early 2008: Operation for science 5 years • Milestone towards a KM3 underwater detector Candidates for first undersea neutrino !!
Indicates good angular resolution μ Zenith angle distribution After quality cuts 5 lines 2007 data No alignement number of events ANTARES PRELIMINARY cos q
μ 5 line detector displays
Toward the -Telescope • EU funded the joint activity for a European-scale Design Study for a km3-telescope in the Mediterranean Sea • KM3NeT: ANTARES-NEMO-NESTOR consortium http://www.km3net.org/ • The experience gained will contribute to the advancement of the KM3NeT activities
CRAB CRAB VELA SS433 SS433 Region of sky observable by Neutrino Telescopes John Carr ANTARES (43° North) AMANDA (South Pole) Mkn 421 Mkn 501 Mkn 501 RX J1713.7-39 GX339-4 Galactic Centre
Quest for cosmogenic n • Motivated by indication of GZK feature in UHE cosmic-ray spectrum • Cosmogenic n (from p + g2.7 n + p+ n) • Probe evolution, composition, spectra of extra-galactic cosmic-ray sources • Goal: >1000 km3sr, > 100 events/yr, E >1018 eV • RICE, AURA, ANITA, ARIANNA at this conference • Acoustic detection in Ice another possibility Tom Gaisser
Pure protons Mixed Cosmic rays Neutrinos Model dependence of cosmogenic n N. Busca
>PeV n absorbed in the Earth Earth-skimming n E. Bernardini Tom Gaisser
~30 atm Neutrinos: important bi-product in Auger A neutrino can induce a young horizontal shower ! Karl-Heinz Kampert h ν µ h em 1 atm
EeV ntdetection with Auger et al. D. Gora <~ 1 GZK nt / year in Auger Gct ~ 100 km for Et ~ 2 x 1018 eV followed by t-decay shower T. Weiler, D. Fargion Tom Gaisser
HiRes limit 1018 < En < 1019 eV slightly above Auger limit --Kai Martens Current upper limit from Auger Oscar Blanch-Bigas Tom Gaisser